Table H-7Strength of evidence for the comparative efficacy of ICSs and LTRAs

Number of studies (# of subjects)DesignQualityConsistencyDirectnessResults (magnitude of effect)Other modifying factorsOverall strength of evidence
Overall total of trials: ICS compared with LTRA
22 (9,873)RCTsFairConsistentDirectICS > LTRA; ICSs had less rescue medicine use (%rescue free days: SMD − 0.25; rescue medicine use per day: SMD −0.23), fewer symptoms (% symptom free days: SMD −0.21; lower symptom score: SMD −0.28), less frequent exacerbations (SMD −0.17), and increase in quality of life (AQLQ scores: SMD − 0.19). All were statistically significant favoring ICSs (Appendix I).NoneHigh
FP compared with ML
9 (3,864)RCTsFairConsistentDirectFP > ML; had less rescue medicine use (% rescue medicine free days: SMD −0.25), less symptoms (%symptom-free days: SMD −0.24; lower symptom score: SMD −0.24), fewer exacerbations (SMD −0.17), and greater improvement in quality of life (AQLQ scores: SMD −0.15). All were statistically significant favoring FP.NoneHigh
BDP compared with ML
6 (3,823)RCTsFairConsistentDirectBDP > ML; had fewer exacerbations (SMD −0.15, 95% CI: −0.30, −0.00), and a trend toward less rescue medication use (mean change puffs per day: SMD −0.08, 95% CI: −0.19, 0.04) and fewer symptoms (%symptom-free days: SMD −0.11, 95% CI: −0.25, 0.02)NoneModerate
BUD compared with ML
3 (520)RCTsFairSome inconsistencyDirectMixed results: reported outcomes either not significantly different or favored BUDNoneModerate
FP compared with ZAF
4 (1,666)RCTsFairConsistentDirectFP > ZAF; less rescue medicine use (rescue medicine free days: SMD −0.30, 95% CI: −0.40, −0.20); fewer symptoms (%symptom free days: SMD −0.29, 95% CI: −0.39, −0.19; greater improvement in symptom score: SMD −0.31, 95% CI: −0.41, −0.21), and fewer exacerbations (SMD −0.21, 95% CI: −0.31, −0.11)NoneHigh

Abbreviations: AQLQ = Asthma Quality of Life Questionnaire; BDP = beclomethasone dipropionate; BUD = Budesonide; CI = confidence interval; FP = Fluticasone Propionate; ICS = Inhaled Corticosteroids; LTRAs = Leukotriene receptor antagonists; MA=meta-analysis; RCT= randomized controlled trial; SMD = standard mean difference; SR = systematic review; ZAF = Zafirlukast.

From: Appendix H, Strength of evidence

Cover of Drug Class Review: Controller Medications for Asthma
Drug Class Review: Controller Medications for Asthma: Final Update 1 Report [Internet].
Jonas DE, Wines RCM, DelMonte M, et al.
Portland (OR): Oregon Health & Science University; 2011 Apr.
Copyright © 2011 by Oregon Health & Science University.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.